A number of different types of molecular model construction are known and are used for the demonstration of chemical molecular structure and to study the interaction between a large molecule such as an enzyme and its substrate. Many of the models currently in use are the well known--ball and stick models in which balls representing atoms are connected by rigid or flexible connectors representing valence bonds.
Using such models it is possible by tedious manual construction to assemble space filling representations of molecules. Other models currently in use include space filling atoms such as the well-known Corey-Pauling-Koltun (CPK) components which are made up of individual components fabricated of plastic or other rigid material representing the space filling nature of individual atoms on a scale of 1.25 cm/angstrom. These models must also be individually assembled from the construction units representing single atoms, involving tedious manual manipulation by highly skilled personnel.